1. Field of the Invention
The invention relates to a method of inducing hair follicle neogenesis by using a skin extract. More particularly, the invention also relates to a method of inducing hair follicle neogenesis by using a protein composition.
2. The Prior Arts
Prior arts for hair follicle (HF) regeneration can be classified into three methods, including (i) implantation of a large number of hair follicle dermal papilla cells, (ii) induction of HF neogenesis by creating wounds in the skin, and (iii) transplantation of folliculoids that are generated in vitro. In the first method, dermal papilla cells (DP cells) must maintain aggregate form during growth to retain function of HFs. Many researches employ this concept with various approaches to promote aggregation of large amount of DP cells then transplanting into the skin of animals. However, the transplantation site of cultured DP cells must be in close proximity to the epidermis to induce HF neogenesis, which increases difficulty in clinical application. In the second method, a suitable size of surgical cut is created on the animal skin to generate an environment that simulating HF development at the embryonic stage. Neogenesis of HFs and hair shafts will appear at the cut site and the regenerated HFs has the characteristics of hair cycle. However, part of the skin must be excised when this method is used and thus clinically unsuitable. Furthermore, this method has not been successfully proved in human. The third method is production of HF microtissues in vitro using polymers or hydrophilic gel as substratum. However, preparation process of such substratum is complicate and successful induction of HF neogenesis is achieved when embryonic or newborn cells are employed.
The drug for treating baldness on the market does not have good effect for the patients with severe hair loss and alopecia areata. So far the method of inducing hair follicle neogenesis in adult is to culture autologous hair follicle dermal papilla forming a cell cluster, and to transplant the cell cluster under the skin inducing hair follicle neogenesis. However, the method of inducing hair follicle neogenesis is too inefficient to be useful in treatment.
In hair follicle neogenesis process, it needs both a certain amount of hair follicle dermal papilla cells and epidermal cells to have the ability of inducing hair follicle after mixing each other. Therefore, according to the concept, many studies intend to mix hair follicle dermal papilla cells and epidermal cells in different proportions, then to transplant into a patient needed. However, it spends more time and cost obtaining the patient's hair follicle first and isolating hair follicle dermal papilla cells for a large-scale culture in the process. Thus, for the purpose of saving time and cost, it is necessary to develop an efficient and convenient method of inducing hair follicle neogenesis.